Electrical Info for Husaberg Motorcycles

This electrical information is for Husaberg motorcycles. We start with a look at the later Kokusan Ignition system, and then move back in time to SEM ignition motorcycles, which were on motorcycles up to 2003. For additional information and questions about the Husaberg electrical system, check out the dedicated Husaberg Electrical forum.

Kokusan Ignition Systems

Setting the TPS

It’s very unusual to have problems with this system, recheck the soldered joints on the stator, 2004 stators were prone for desoldering, but usually on the alternator side.

Check the resistance between Red/White and Black/Red should be around 15 Ohms.

Check between Red and Green should be around 100 Ohms. (pick up)

Check the secondary resistance of the HT coil with out the cap around 5000 to 6000 Ohms, put you meter setting on 20K, then test between the HT lead on earth, this should give you the secondary resistance.

Check the Blue feed wire to the coil and all other connections.

Also check the main bunch of Brown earth wires that are near to where the Blue coil feed is.

To reset the TPS on the Keihen carb, the engine has to be idling at manufacture’s spec – 1,800 RPM. Disconnect the plug from the TPS measure the resistance across blue and black wires it should be 750 Ohms + – 25 Ohms at 20°C or 68°F. (Sparks). There are two readings to be taken, the first is often close to 750 but it’s been found to be nearer 1100-1200 instead of 750 at the second (DaleEO).

Calibrating the Electronic Speedometer

If you want to change WS and you Husaberg is enduro running a battery you need to disconnect this but there needs to be a back up battery in the speedo. Remove the head light number board and locate the three wire triangular plug, pull this apart and with a jewelers screw driver relieve the plastic tab this will allow you to remove the black wire (female plug). Now when you get up the set up menu you will now see the WS icon press the mode button until the WS starts to flash then with the – and + buttons go up and down until you get the right numbers. Punch in the numbers 1790 this is now recalibrated for 17 inch wheels. Now push the black wire back into the the plug and reconnect the battery. (Sparks)

Pre 2004 Conversion from SEM to Kokusan Ignition

SEM

How It Works – SEM Ignition System

The stator contains two sets of coils – the trigger coil and the magneto charge coils.

The charge coils put out about 10 AC cycles per engine revolution at 200VAC and this is fed to the CDI/coil unit under the tank. In this unit there is a rectifier which points all the AC pulses in the same direction to make DC at about 300V. This DC is fed across a capacitor of about 1 microfarad which stores the charge like a tiny battery.

When the crank gets to a pre-detemined position (set by “timing” the engine) the trigger coil puts out its only pulse per revolution at up to about 20V to the CDI unit.

In the CDI there is an analogue timing circuit (note; it is rarely a microprocessor in magneto systems) that puts out the signal to fire the plug a time (ie number of engine degrees) after the trigger coil fires. The change in lag time of the timer is what gives the spark advance curve. The amount of time this lag happens (ie the function or “curve” of engine speed versus spark timing) is dependent on engine speed and the electronics in the timer circuit.

I imagine that different CDI units could have different spark timing curves. You would probably want different spark curves between the 400cc and the 600CC bikes of the same year. Some models of bike have a switch on the handlebar which gives you the option of two different spark curves.

Anyway, when the timer puts out the signal to spark, it triggers (or switches on really really fast) a Silicon Controlled Rectifier (SCR) to dump the entire 300V stored in the capacitor through the primary winding of the ignition coil. This causes a very fast rise: a 30,000V spike in the secondary winding which goes straight to the spark plug to create the spark.

Flywheel and stator from KTM LC4 motor. This is the same ignition unit used on 2003 and earlier Husaberg motorcycles, with exception of lighting coil wattage output. (Sandskipper)

After the capacitor is discharged the SCR switches off and the capacitor recharges ready for the next revolution. What does come from this is that a spark IS a spark, but it’s the timing with the crankshaft that’s just as important. I suspect that using a different CDI/coil unit from original will change this timing as the spark advance curve is “built into” the CDI electronics. It takes better people than I to know wHether this is a good or bad thing. (Brad/Bundybear)

The pulse that generates the spark is initially supplied from your generator. In a nutshell – two coils provide the power level A, the third coil is power level B, all in one revolution of your motor. The ignition module monitors the difference and uses the generated power of power level A to create a spark. So the engines own revolution determines at which point the spark is created – Not the ignition module – hence IMHO many of them should be compatible. (Ady)

It’s the difference in the generated voltages in the primary coils that is monitored by the ignition module. For example if there are 3 primary coils on the stator, as the engine spins the magnet over the coils. coil 1 may produce 2v. coil 2 may then produce 2v, coil 3 however may produce 5v. That would then be one full rotation of the flyweel. The difference in voltages is picked up by the micro-processor in the ignition module which then sends a small signal to the capacitor which draws the power from primary coil 1 (2v) and primary coil 2 (2v) then discharges its high amperage AC load to a step-up transformer which gets all excited and charged up only for it all to happen again so it then has to discharge all that voltage down to the nearest earth – your spark plug. The cycle has began again. The only moderating thing is the timer circuit you describe, that is purely used to synchronize the time of the spark to create even distribution. (Ady)

Early (small coil) SEM ignition systems were analogue. The ignition curve was simply a product of rpm. Increase rpm and the trigger signal is generated earlier and consequently: “ignition advance”. Second generation SEM systems (i.e. Digital Force) had two independent curves based entirely upon engine rpm and handlebar switch location. SEM solid state hardware be it digital and / or analogue is contained in the coil housing.

SEM Basics

RPM dependent capacitor charge voltage generated by the ignition charge winding located in the stator (usually between 30 and 300 volts DC) is stored in the coil housing capacitor. A thyristor awaits a pre determined voltage signal from the ignition trigger winding also located in the stator. Once minimum trigger voltage is met the thyristor releases the stored capacitor charge via the ignition coil primary windings. Said charge is stepped up to 30K volts (plus/minus) via the ignition coil secondary windings.

RPM

Capacitor Charge (Volts)

Ignition Trigger (Volts)

200

14.5 – 17.5

1.0 – 1.5

525

47

4.0

1,150

92

8.0

The capacitor charge coil provides a wide range of voltage levels (RPM dependent). During cranking said voltage is well below 100. However, enough to boost the ignition jumping a 1.5 mm plug gap in open atmosphere. Trigger voltage levels also vary considerably with rpm. Most often the minimum trigger threshold has proven to be in the neighborhood of 3.5 volts. Unfortunately, many “New” SEM stator units will not provide said minimum trigger voltage during electric start as rpm is too low. Hence the SEM equipped Husaberg which will boot start yet fails the “E” start test. I once used a stun gun generator to pre charge the capacitor as I was first under the impression ignition output during cranking was insufficient. What I learned was trigger threshold output was the culprit, not lack of secondary voltage. (Lineaweaver)

Wear Limits Stator

How to Start It?

If only we could guarantee this for you! In the meantime though, here are some hints! There are many things to try, another one is the Taff’s Crescent Mod on the kickstart mechanism. This gives a longer kick.

Plug Cap

Despite the service book recommending a new cap regularly, few owners bother yet often struggle to start their machines… say no more! Silicon both ends of the HT lead where both sleeves go over either the cap or plug.

Yuasa YTZ7S or CTZ7S Conversion

The YTZ7S batteries are 6 amp with cold crank of 130, the original YTX5L-BS is 4 amp with a cold crank of 70 (yoshie). Use an Optimate battery charger (see handy tools) to keep the battery topped up between rides. All kinds of prices are banded about, but have a look at this thread for the pitfalls of the conversion. The YTZ7S is a Gel-Cel battery and is nearly the same size as the YTX5L-BS. It’s actually about 3mm wider so to fit it, break the poorly welded tray the battery fits into at the joins. The CTZ battery is an AGM (absorbent glass fiber matting) battery and is allegedly better still than the YTZ with 160CCA. See here for a view on both.

Second Battery

Second Earth

For 2003, a second earth was fitted from the battery earthing to the frame. This is a back cure for SEM’s, and not a forward cure for the 2004 models onwards.

Orange Kill Wire from Stator

The wire feeds straight from the charging coils and carries a fair bit of voltage, as Bundy found out.

Wiring Removal

Miles of wiring can be removed including the ugly wiring down near the starter relay and battery. There is a lack of lugs around the headstock from which to support the wiring harness, so use extra large cable ties for support. Hours can be spent re-routing the wiring harness for a good clear run but it is worth the effort as good wiring also looks better.

Regulator

Gets covered in mud. At a stretch and with an extension to the wiring, it can be moved to under the seat and relocated to the central bolt, this was standard for the last SEM year (2003).

Ignition Barrel Removal

This can be done when they become faulty or get knocked about in a fall.

Flywheel Marks Wrong

TDC tool in parts (Simon)Mark the new scratch with say – tipp-ex and now you’re ready to strobe the engine.Remove the protractor and now use a ruler and a scriber to mark the flywheel in a line toward the center of the crank.Mark a scratch across the top of the flywheel with a pencil or whatever temporarily.…and then turn the engine gently till it touches the ‘dead-stop’ the other way. Adjust the protractor until the numbers read the same ‘before’ and ‘after’. Your ‘0’ is now the real TDC.Fit the protractor on the flywheel using blobs of blue-tac. Suggest you immediately set the ‘0’ to the right of the right line by 5d. Now we turn the engine using a T-bar or a wrench bar gently till it stops against the stop one way…You can see the original pair of lines through the sight hole on the ignition flywheel. The one on the left is the original TDC, the one on the right is the original 5d BTDC. You are going to have a new line to the right of this pair – equidistant away probably.Forget the white blob by the owner, you can see the deep groove has been painted white. This is your timing mark on the stator. Move the old TDC marks down to BDC and fit the ‘dead-stop’ tool and also a screw with a pinch nut and a little pointer in the direction of the center of the crank.This is an alloy tube, threaded at the end with a hollow center for a steel pin. The steel pin sticks out about 30mm into the chamber and has a domed tip to avoid damaging the piston. A pinch screw to keep the steel pin still can just be seen to the right.

Ignition Timing

Use a strobe with a timing adjustment knob. Set the timing so that the line on the flywheel meets the mark in the spy-hole using the adjustment knob. Half this figure is your advance (i.e. 72° that means it is 36° advanced) (Lineaweaver). Read more about ignition timing using a strobe.

Head Lamp

Starter System Removal

This is very easy and takes just an hour. Buy an alloy bung from your Husaberg dealer to fill the hole left by the starter when you remove it and the solenoid. Disconnect the two leads, remove the battery and all mounts etc, disconnect the solenoid wires and that is it! Despite the rumors, the bike will still stop on the kill switch or ignition key. Here’s how to run your Husaberg without a battery.

Weak Starting?

This can always be a problem but it was mainly with the SEM ignition bikes that we struggled. Things were ‘beefed’ up for 2003, the last SEM year. This is some number crunching and stats.

Another member has discovered that the wires to and from the battery terminals are not good enough: “I can finally ‘one-kick’ it but I never have too. 8-gauge wiring from the negative terminal to frame, and from the negative to engine, 6-gauge from the positive terminal to the solenoid and then to starter. I have turned the engine over 100 times (separate short cycles) without having to put the battery on a charger once. In the past I kept it on the charger and had to wait between tests for it to give me another try or two.” (Unomecin)

I went with the IXU24 and it really helped the motorcycle to start. A well carbureted motorcycle which might be correctly (read: leaner than delivered but still CORRECT!) will see one of these expensive spark plugs last 3-4 years plus of racing, trailing etc. OEM jetting is generally on the rich side and so a fresh plug every year to be safe wouldn’t go amiss as the OEM mixture of rich starting and heat in the upper revs really kills plugs.

Ignition Cover – Defeat Water Ingestion!

Wiring tube splits-plastic is brittle so the tube should be replaced, the wires can be fed through one at a time using some welding rod a s a ‘rodder’ or lockwire. “Shepherds crook” the tube over to stop water entering and silicon and zip tie both ends. Feed the cable around the back of starter motor or close to the oil filter.

To stop getting moisture in: silicon the side cover on and then don’t remove. Also, drill a hole in crankcase from underneath, this should be 6mm OD and done at the back of the flywheel housing. This will help it self-dry. I used to fit loose split pin to keep the hole ‘clear’ but it’s not necessary and the hole is never bunged up! A running engine will push the water out if it ever got in. Cover the stator and flywheel weights in petroleum jelly, this stops rust.

Fusebox

Change to a “staple” type fuse as the clip in type come loose and blow a fuse.

To Run DC – No Battery

A tremendous in-depth look on this thread with great input from Bundybear. It’s possible to run the bike without the battery and all is easy to remove. Remember to disconnect the orange wire at the cdi/coil if the ignition system is ok then it should produce a spark (Sparks).

Positive HT Leads

Split open in red. Replace with 2003+ plasticoated clear wiring.

MX (470) – Weaker Spark

MX Husaberg had stators without lighting coils, ie slimmer, and if the spacers were not fitted they would run but had a much weaker spark. (NTB Racing)

Husaberg 470 Stator Spacer

Radiator Fan

All 2006 Husaberg motorcycles now have the facility to fit a fan so all parts to do the job ‘dead proper’ will now be available, however we used to bodge it ourselves! And this fan kit is cool!

The High/Low Story

When flicking the switch with the strobe working, you can see the flywheel visibly at a totally different point at tick-over. I dyno’d the two settings and despite the brochure blurb that the difference was only at low revs, i can report that in LO I gained at the bottom and lost at the top: the opposite of the HI position.

The Husaberg STATOR is a Greek Epic of Colossal Proportions!

Stator/Ignition

No spark. Stators can lose varnish, go rusty, split and crack open and finally die sometimes. You’re lucky or you’re not! I had my first for 4-years and only changed the flywheel, the stator lasted 4 1/2. It’s heat related (Lineaweaver). Check out this discussion on stators.

Ignition

Stator Wiring

Is as follows: yellow into a double red (1 into a 2), second yellow into a red/white or can go straight to the regulator (a finned alloy box) which has the wire coding marked on the back, light blue into a brown or to the earth carousel, red to red, black into black and green into green.

Stator Wiring Diagram: The red bubble shows the charging coils for spark. The green bubble denotes the trigger coil for spark timing. The yellow bubble shows the lighting coils for the operation of all lighting of the Husabergs. (Sandskipper)

KTM and Other Stator Correlation

Carbonone ordered the KTM part number 580.31.002.050 from his local dealer for $160 and it fitted straight in with no modification. This is the part # for a KTM LC4 and will work on all 1998 and prior bikes. Make sure the black to green measures 23 Ohms as some of the last models measured 165 Ohms. Anything from 1999 to 2003 will have to be from Husaberg, as the SEM stator for these years was a one off and wasn’t fitted to anything else.

Stator Test Figures

Prior to 1999

1999 to 2003

Black to Red

1750 Ω

3000 Ω

Black to Green

23 Ω

165 Ω

All measured at 20°C and all + – 10%

The Plastic Coating

The plastic like matrix is only good for so many heat (expansion) cycles. (Mikst)

The Stator will continue to work minus the wrapper. For many years I had both stator and flywheel cryogenically treated. Said treatment improved low rpm spark output via a reduction in fine wire resistance. Unfortunately the “deep freeze” caused severe cracking making the end user a bit uncomfortable (Lineaweaver).

The Flywheel

Three Phase Regulator Rectifier

Measuring the Resistance

The spec is less than 1 ohm between the blue wire and the 2 yellow wires when the yellow wires are connected in parallel (together). I measured 0.8 ohm between the blue wire and the 2 yellow wires, when the yellow wires are connected in parallel (together). I measured 1.2 to 1.3 ohms between the 2 yellow wires, and 0.9 ohms between each individual yellow wire and the blue wire. The yellow and blue wires were all insulated from the stator laminations over 20 meg ohms. These were measured with the stator out of the bike on the bench, using an inexpensive digital multimeter. The black to red and black to green are the ones that make the bike run. The yellow and blue are the ones that charge the battery and make the lights work. Red to Black should be 3000 Ohm +-300 Ohm., measured at the connector on the stator. You should install it however long enough to kick the engine over while measuring the Red to Black AC voltage (preferably with a peak hold type of DVM). The voltage should be 35 VAC nominal, hopefully not less than 30 volts. My Husaberg would not start at 24.9 VAC, when I used the e-start with the spark plug removed. (JoeUSA)

If you have a multimeter check for up to 14 volts AC between blue and yellow charge wires with it running. Disconnect rectifier do same check – should get up to 20V AC. Check connections from stator to the rectifier. Check for up to 14V DC coming out of rectifier. It is possible your regulator has died shorted out. Disconnect it and repeat this check. Check wiring from rectifier to battery. If the system is charging you should see about 14.1V DC or so across the battery with it running. These bikes must not ever charge properly from new as less than 13.8V will never bring a battery up to full charge!!!! Less than 13V will barely charge the battery if it was flat. I modified mine to give 14.1V or so. Typical carbon plug leads have a resistance of 10k ohms per foot of length and the same for the cap. (Bundybear/Brad)

Wire bundle coming from the stator to the CDI coil. The earth carousel is also shown. (Sandskipper)